LR Bite vs Cross vs Drive

[Bcollins82]

So would a turn in and out each corner be better than just adjusting LR?

Yes, in my opinion that's absolutely the best way to do it. Always try to adjust wedge on the scales so you can keep your ride heights the same if you have the option. Obviously you can't do that at the track, so adjusting all 4 corners is the best option there. Some people play on the scales to find how far to turn each corner to achieve X amount of change, but I have always preferred to make other changes at the track if possible.

[drtrkr244]

I've been using Joe Garrisons method for years and it works on all cars.
1 round in RF, 1 out LF, 2 in LR, 2 out RR= 50lbs more bite.

I usually do 1/2 of these to get 25lbs more.

[Nobody]

Jesus, I just lost a 2 page post, trying to explain this better, LOL.

I'll try to retype it later, sorry

[gaz05]

Have been reading this with interest, is there a percentage of cross weight where its too high, eg 52% or should it be in the high 40s ?

[DirtRacer9x]

Well any input please help with. I'm still wanting to have it explained when the strap is right how I'd have more drive even though I'm not touching the spring. Also isn't there other ways to keep spring loaded and have drive. Example like not hike as much and have more cross, have less front rebound, or more lr bite etc? Or does having a gas charged shock act as a spring at say 30-45lbs of rod pressure?

[dfhotlm33c]

The scientist in me wants to see an empirical study....
Set your car up at ride height with the amount of LR bite you normally run with.
Put the car in full hike position...use a long rod instead of a shock perhaps and get the left rear where it would be at full hike...use a chain or other mechanism to compress the right front to its dynamic position on exit of a corner, including accounting for countersteer..as well as the right rear..(Use your travel indicators on your shocks as the guideline for where these points would be)..even compress your fifth coil to its position when you are at full hike...Now put it on scales. determine your weights...put back to ride height...crank a bunch of extra bite in it, or as some are saying, go the opposite direction and put 100 lbs RR in it...put it back to full hike position...measure again...see if there is a change..
this wouldn't be perfect...it would require a set of rollers like on a chassis dyno, and person in the drivers seat mashing the throttle to truly mimic wrap up and other factors and variables (hmmmm....there's an invention for someone to create..a set of "dynamic" scales that would allow you to truly measure the weight movement under given conditions...or better yet..some chassis data acquisition package that would use the basic principles of physics and sensors to provide you with that information on a test car at the track.)
We could all speculate all we want but this is one to "prove" one way the other...

[keeks]

Question......If I were to try and mimic the position of the car statically say using ratchet straps to achieve my shock and spring compressions, would I strap the car to itself, or to the ground?

I'm thinking I would have to have floor anchors and pull the car down to mimic the forces produced during racing.

[DirtRacer9x]

There is no way to mimicking what the car would be doing. Simply doing travel of spring would let you know how much weight is placed onto each spring but all the ballast weight is moving as well. That's my thinking on that at least.

[DirtRacer9x]

But as for lr spring should I always have it loaded? Because once it's unloaded any turns at all I don't believe affect total drive once hiked. I believe there will be a difference from spring loaded to unloaded but overall hike and added drive won't be different. I think Initial on throttle drive may go up because yes you have added cross but you're ending up off the spring still with the same hike. So should I always have the car on the spring even if its compressed just 1/8-1/4". Meaning take hike out of the car and change maybe some calving instead on shocks?

[c.mac.4]

Question......If I were to try and mimic the position of the car statically say using ratchet straps to achieve my shock and spring compressions, would I strap the car to itself, or to the ground? I'm thinking I would have to have floor anchors and pull the car down to mimic the forces produced during racing.

not with any kind of accurate results... you would have no way to simulate engine torque, 5th arm/pullbar effects, or even inertia pulling the car sideways. HUGELY critical variables.

[setup479point2]

Just wonder what kind of late model chassis has an unloaded LR spring , with anything over 125 lb. of bite? I've never worked with one .

[Bcollins82]

Just wonder what kind of late model chassis has an unloaded LR spring , with anything over 125 lb. of bite? I've never worked with one .

No kidding... I was always pulling the limit chain loose at the axle so I can get more rounds in because it's preloaded so hard.

[DirtRacer9x]

Just wonder what kind of late model chassis has an unloaded LR spring , with anything over 125 lb. of bite? I've never worked with one .

Actually this is for a mod. I find late model guys know more and have more experience than most mod guys. So that's my main reasoning. Not familiar with late model chassis at all on dirt but know they usually use lift bar and pull bar rear end set ups and front end is rack and pretty much allCustom. So on late models you guys run more or less hike in lr and how do you keep it loaded still? Are bar lengths longer or shorter for you compared to lost mods I've seen 16-17 uppers and 14-15 lowers. Thanks.

[drtrkr244]

Just wonder what kind of late model chassis has an unloaded LR spring , with anything over 125 lb. of bite? I've never worked with one .

2009 Rocket blue/gray always had 3/4-1" of threads left. In fact, that was a common adj. to run down adjuster to the spring, when the track slicked off.

[setup479point2]

2009 Rocket blue/gray always had 3/4-1" of threads left. In fact, that was a common adj. to run down adjuster to the spring, when the track slicked off.

Interesting , haven't yet worked with a blue/gray . Currently have a black , blue / gray must have a bit different drop . Learn something every day. So for slick you added about 70 lb. more bite .

[drtrkr244]

Interesting , haven't yet worked with a blue/gray . Currently have a black , blue / gray must have a bit different drop . Learn something every day. So for slick you added about 70 lb. more bite .

We ran that a few races but ended up running the stacked spring on the LR.

[DirtRacer9x]

So you do a stacked set up so its like a take up spring? What rates do you usually use for this set up? Ball park?

[7uptruckracer]

Don't confuse stack with a Dual Stage setup.

So you do a stacked set up so its like a take up spring? What rates do you usually use for this set up? Ball park?

[Bcollins82]

So you do a stacked set up so its like a take up spring? What rates do you usually use for this set up? Ball park?

A stack is not like a take up spring. A stack is normally a shorter, stiffer spring on top, with a free floating collar between it and the lower spring. It just makes a long, soft spring that doesn't bow like a normal long, tall spring would. You can use any combination of rates, then use the formula to calculate the rate. The formula is (spring X spring) / (spring + spring)= stacked rate, so if you have a 400 on top of a 200 it would be 200 X 400 / 200 + 400 = the stacked rate, so 80000 / 600 equals a 133.3 lb spring. That combo 400 over 200 is what Mastersbilt reccomend to us for a stacked combo back in the day.

[Bcollins82]

Well are you guys using a stacked set up or 2 stage?

Dual stage is mostly used on the RF, stack is mostly used on LR.